Friction clutch assembly

ABSTRACT

Friction clutch assembly for motor vehicles, tractors, equipment carriers and similar vehicles having a first friction clutch for engaging and disengaging a gear-change transmission, a second clutch for an additional drive, each of the clutches including a friction disc, a spring-loaded pressure plate having a friction surface and being coordinated with each of said friction discs, respectively, an axially fixed structural unit for connecting the second clutch to a flywheel, torque or transmitting means located in a power transmission path between the flywheel or the axially fixed structural unit, on the one hand, and the pressure plates, on the other hand, and a disengaging lever system for each of the clutches, the disengaging lever systems having a respective disengaging means, the pressure plate of the first friction clutch and the pressure plate of the second clutch being mutually exchangeable in another assembled condition of the friction clutch assembly, the pressure plates respectively having receiving and engagement means for receiving the disengaging means of either of the clutches in which the respective pressure plates are then assembled, and engageable by the torque transmitting means in whichever clutch the pressure plates are assembled.

United States Patent 1 Maucher July 31, 1973 1 1 FRICTION CLUTCHASSEMBLY [75] Inventor: Paul MaucherfSasbachffiermany [73]" 'AssigiieezLuK Lamellen und Kupplungsbau 6 m, .Bphl/B qm G m [22] Filed: Sept. 20,1971 21 Appl. 1%.: 181,690

[30] Foreign Application Priority Data Sept. 18, 1970 Luxembourg 61710[52] US. Cl. 192/48-8, 192/70.l3, l92/70.18, 192/70.29, 192/89 B, 192/99A [51] Int. Cl. Fl6d 13/40, Fl6d 21/02 [58] Field 01 Search 192/48.8,70.13, l92/70.l8, 70.29, 89 B, 99 A [56] References Cited UNITED STATESPATENTS 2,371,804 3/1945 Cooke 192/48.8 3,212,611 10/1965 Ruofi' etal.... 192/70 X 3,061,062 10/1962 Smirl 192/70.18 3,590,968 7/1971Binder 192/48.8 2,993,576 7/1961 Carlin et al. l92/70.13 X 3,215,23311/1965 Smith et a] 192/48.8 X 3,554,342 1/1971 Spokas 192/70.18

lrin ary Examiner-Allan D. Hermann [5 7} ABSTRACT Friction clutchassembly for motor vehicles, tractors, equipment carriers and similarvehicles having a first friction clutch for engaging and disengaging agearchange transmission, a second clutch for an additional drive, eachof the clutches including a friction disc, a spring-loaded pressureplate having a friction surface and being coordinated with each of saidfriction discs, respectively, an axially fixed structural unit forconnecting the second clutch to a flywheel, torque or transmitting meanslocated in a power transmission path between the flywheel or the axiallyfixed structural unit, on the one hand, and the pressure plates, on theother hand, and a disengaging lever system for each of the clutches, thedisengaging lever systems having a respective disengaging means, thepressure plate of the first friction clutch and the pressure plate ofthe second clutch being mutually exchangeable in another assembledcondition of the friction clutch assembly, the pressure platesrespectively having receiving and engagement means for receiving thedisengaging means of either of the clutches in which the respectivepressure plates are then assembled, and engageable by the torquetransmitting means in whichever clutch the pressure plates areassembled.

50 Claims, 9 Drawing Figures J 32/ 5 nd II 5 I" 5' if ,1 T11. a I M I ll a 2 Y a M 7 W E 10 7 II A E in 4f l0- M M 11- 5 A M 10- M jg 2/ I If 9J J 1 122.7 ,f

PATENTEDJUL31 192s SHEEI 1 [1F 5 Fig. 7

PATENTEDJUL31 ms SHEET 3 [1F 5 PATENIEDJULIH I975 3.749213 SHEET [if 5FRICTION CLUTCH ASSEMBLY The invention relates to a friction clutchassembly for motor vehicles, tractors, equipment carriers and similarvehicles, having a friction clutch for engaging and disengaging agear-change transmission, a further clutch for an additional drive, suchas a power take-off. A friction disc is provided for each of theclutches with spring-loaded pressure plates therefor, equipped withfriction surfaces, the further clutch being connectible through anaxially fixed structural unit to the flywheel of, for example, aninternal combustion engine. The clutch assembly is also provided withtorque transmitting means which are located in the power transmissionpath between the flywheel and/or the axially fixed structural unit, onthe one hand, and the pressure plates, on the other hand, and each ofthe pressure plates is equipped with means for receiving the shifting ordisengaging means assiciated with the shift or disengaging lever systemof the same.

Friction clutches or dual clutches with these features, such as havebecome known, for instance, through German Petty Patent No. 1,996,835,1,791,881, 1,780,482, 1,628,607; German Patent No. 819,777; GermanPublished Patent application No. 1,294,228; the German ProvisionalPatent No. 1,425,326 and French Patent No. 1,461,841; 1,381,432 and1,364,142 are used, as aforementioned, in special purpose vehicles suchas tractors, equipment carriers, construction machinery and the like,wherein the operation of the two clutches can take place separately orsequentially depending on the application and the construction of theshift lever systems. In dual clutches which can be operatedsequentially, three levers are as a rule associated with the shift leversystem, while in dual clutches which are operated separately two groupsof levers are used as a rule, each consisting of three levers. Fortorque transmission, either leaf spring elements are provided, or thepressure plates are provided with radial profiles, such as projections,which are receivable or engage in oppositely profiled structures, suchas in guide slots that are machined into the housing, for example.

The pressure plates for the individual clutches of a dual clutch exhibitin practice considerable differences as to mass or thickness. Thepressure plate for the vehicle drive should have a large cast-metal massin order to assure an appropriately large heat capacity or heat removalfrom the clutch disc, whereas the pressure plate for the power take-offrequires only a small mass, because only relatively little switching orshifting energy is generated therein.

Although a multitude of dual clutches of similar construction exhibitmutually similar dimensions as well as pressure plates and discs of thesame size for the respective regular vehicle drive and auxiliary drive,the dual clutches for the individual vehicle types, depending on thetype of construction of the latter, are designed so that the respectivefriction clutches for the vehicle drive are sometimes located on theside coordinated with the flywheel, and again at other times on the sidefacing away from the flywheel.

Differently constructed pressure plates, actuating and shifting means,differently constructed axially fixed structural units, such as thehousing or the intermediate disc, for example, and differentlyconstructed torque transmitting means are therefore required for bothtype of clutches.

It is accordingly an object of the present invention to assure uniformand therefore economical production of dual clutches of the typedescribed hereinabove, and more specifically so that virtually all ofthe aforementioned components can be employed as well for either clutchtype. Furthermore, it is an object of the invention to assure that, forexample, in the case of (plate or disc) spring clutches, such as aredescribed in German Published Patent Application No. 1,294,228, theplate spring in both assembly positions of the pressure plates,

always abuts with the larger contact diameter thereof against thepressure plate for the vehicle drive.

With the foregoing and other, objects in view, there is provided inaccordance with the invention, a dual clutch of the aforementioned typewherein each of the pressure plates has receiving and engagement meansat which, in reversed assembly condition, the disengaging or releasingmeans respectively associated with the other pressure plate as well asthe torque transmission means can be received.

in this connection, the arrangement or positioning and the constructionof the releasing or disengagingmeans must be selected so that theengagement means can be accommodated from the standpoint of spacerequirement.

Although with suitable placement and construction of the disengagingmeans and the receiving and engagement means for the disengaging meansand the torque transmitting means, the features of the present inventionare applicable to all kinds of dual clutches, the physical descriptionof the further features of the invention, for the sake of simplicity,will lean,.hereinaftcr, toward such separately operable dual clutches asare shown in the German Published Patent Application No. 1,294,228.However, the invention is in no way limited to such clutches.

Different possibilities for the construction, arrangement and placementof the engagement means are given, of which several particularlyadvantageous ones will be highlighted hereinafter in accordance withfurther embodiments of the invention.

It, as is the case in the German Published Patent Application No.1,294,228, the disengaging means are pivotally connected directly orindirectly at dogs provided at the pressure plates beyond the outerdiameter of the friction dies, either the same engagement means can beused as the engagement means for the disengaging means of the otherdisengaging system, in the case of reversed assembly condition, oradditional engagement means can be provided at the pressure plates, suchas, for example, dogs, enlargement of the existing dogs, additionalpressure pads, etc. for the disengaging means of the other disengagingsystem, namely, for instance leaf springs, may also be providcd inaddition or else there are provided for the other assembly position ofthe pressure plates additional engagement means for this purpose, forexample, again dogs with which the leaf springs can engage. It isfurthermore possible, depending on the arrangement and construction ofthese engagement means, to use the latter in the one condition ofassembly, for the disengaging means, and in the other condition ofassembly, as engagement means for the torque transmission means.

1n any event, however, it is advantageous in accordance with anotherfeature of the invention, to provide receiving means, on the one as wellas on the other pressure plate, for the receiving means of both systemsand/or the receiving means for the torque transmission means that are atthe same height relative to the friction surfaces, because, in thatcase, uniform torque transmission means and disengaging means can beused for both conditions of assembly.

In accordance with a further feature of the invention, the sameengagement means is used as the engagement means for both disengagingsystems and also as the engagement means for the pressure plates. Forsuch a construction it is particularly practical and, in accordance withthe invention, for the receiving means of the one as well as of theother disengaging system and/or the torque transmission means, or thereceiving mean for the torque transmission means, respectively, to beprovided at both pressure plates respectively at the same angularspacing from one another and/or on the same diameter. Such anarrangement is particularly advantageous also in view of the fact thatthe use of leaf springs and axially projecting dogs as torquetransmission means, as described in the German Published PatentApplication l.294,22'8, is made possible.

When leaf springs are used as torque transmission means, a further,particularly advantageous embodiment, in accordance with the invention,is provided wherein the means at the pressure plates for the receivingand engagement of the leaf springs are located in the middle of theangular range between two adjacent shifting or disengaging means of thedisengaging systems. Since such a construction is not applicable in allcases due to the prevailing space requirements and conditions, it isadvantageous, in accordance with the invention, that at each individualpressure plate the receiving and engagement means, respectivley,provided for the disengaging means of the one disengaging system have arelative angular spacing and/or radial spacing against the receiving andengagement means, respectively, provided for the disengaging means ofthe other disengaging system.

In this connection, it is practical and particularly simple, and inaccordance with the invention, to have the disengaging means of theindividual disengaging systerns offset against each other by an amountwhich corresponds to the mutual offset of the receiving and engagementmeans, respectively, at the pressure plates.

Between the adjacent disengaging means of both disengaging systems,there is provided, in accordance with the invention, at each of thepressure plates, the engagement means for the torque transmissionmeans,i.c., the leaf springs, specifically in the middle of the angular rangebetween the receiving and engagement means, respectively, provided atboth pressure plates, for the disengaging means of one of thedisengaging systems.

In the great majority of cases, it is desirable, in accordance with theinvention, for the engagement means for the torque transmission means,i.e., in particular the leaf springs, to be located in registry with andsuperimposed on one another on the two pressure plates.

A further feature of the friction clutch according to the invention,wherein additional engagement means for the disengaging means of theother disengaging system are provided, is to place the centers of thefastening elements for the leaf springs at the pressure plates in themiddle of the angular range between the center of the adjacentdisengaging means of one of the disengaging systems.

It is advisable, in accordance with the invention, for the engagementmeans for the disengaging means of one of the disengaging systems, inreverse assembly condition of the friction clutch assembly, to serve asengagement means for the leaf spring elements, and vice versa. In thisregard, it is necessary that the engagement means mentioned havesubstantially the same mutual radial spacing therebetween.

A further feature of the invention, is to provide pressure platesconstructed in such a manner that also in the case of reversed assemblycondition, the respective identical engagement means for the fasteningelements for the leaf springs are employed.

In the last-mentioned embodiments it is not absolutely necessary for theengagement means at the pressure plates for the disengaging means of thetwo disengaging systems to be offset against each other; that is, it canbe advisable, according to the invention, in various cases to disposethese enagement means radially behind one another or in series.

Furthermore, the engagement means for the disengaging means of bothdisengaging systems can even be situated, in accordance with theinvention, substantially in registry, as viewed in axial direction, whenassurance is provided that the disengaging means are functionallyoperable, for example, by inserting screws, rivets or the like, intothose bores, that is, the receiving and engagement means, into which, inreversed assembly condition, the disengaging elements of the otherdisengaging system, which are constructed as tie rods, would be insertedor with which they would be engaged. A pin having a diameter larger thanthe hole, can also be used, in accordance with the invention.

It is also advisable, in accordance with the invention, to arrange thedisengaging means of one of the disengaging systems substantially inregistry with and over those engagement means to which the leaf springsare fastened at the pressure plates. In that case, the disengaging meansof this disengaging system, can, for instance, rest on the rivet headsof the fastening elements for the leaf springs.

In this regard, it is particularly advantageous, according to theinvention, that the engagement means for the disengaging means of atleast one of the lever systems and the engagement means for the leafspring elements are provided at a common element of the pressure plate,for instance, a dog.

As mentioned hereinbefore, most of the features of the present inventionare applicable to all kinds of dual clutches, regardless of whether theclutch is constructed as a sequantial clutch with three layers, for example, or as a separately operable clutch with six levers, for example,or whether leaf springsor other ele ments are used for the transmissionof the torque.

However, the invention can be realized in particularly simple manner, inaccordance with another feature thereof, namely in a clutch assembly inwhich a plate spring is provided between the two pressure plates andbears against dogs or bead-like projections at the pressure plates, andin which the flywheel of an internal combustion engine serves asfriction countersurface for one of the friction discs, while thefriction counter-surface of the other friction disc is located in thehousing which at least partially encloses the clutches, and that foreach of the clutches, a disengagingsystem with one or two-warm levers isprovided, the levers being pivoted in the housing, the one-arm leversexerting pressure on one of the pressure plates, and the two-arm leversexerting a pull on the other pressure plate when, in such a clutchassembly, the one-arm levers form a knife-edge bearing, with arespective bearing element provided at the housing.

A particularly advantageous construction of the knife-edge bearing, inaccordance with the invention, is obtained by constructing the bearingelements as bearing blocks which have a wall which projectssubstantially in direction of the axis of the clutch assembly andextends in peripheral or tangential direction, at least one profiledportion thereof being provided against which a suitable counter-profiledportion of the levers is in engagement. Thereby, the levers can besecured in the peripheral, axial and radial direction at the bearingblock. The levers, as well as the bearing blocks can be formed of sheetmetal profiled members.

It is furthermore particularly advantageous and simple, with clutches ofthe aforementioned general construction according to the GermanPublished Patent Application No. 1,294,228 as well as for implementingthe concept on which the present invention is based, to provide thelevers with a contact part for a pressure pin radially within thebearing blocks, the pressure pin being slidingly held in a guide of thehousing and having an end facing away from the contact part and abuttingthe receiving and engagement means, respectively, of the one pressureplate.

lt is advisable to construct the contact part, in accordance with theinvention, so that it is adjustable in height, in order to be able toadjust the time of disengagement of this one pressure plate, to be ableto readjust in the case of wear, and to insure uniform alignment of allthree levers of this lever system. For this purpose, the contact part isarranged in a threaded bushing provided in the lever. ln thisconnection, it is especially simplified, according to the invention, toprovide the threaded bushing with a flange which abuts against the sideof the lever facing toward the housing, while a counternut is providedin the other side of the lever. The contact part is thereby adjustablein height and, furthermore, a positive connection between the contactpart, the threaded bushing and the lever is attainable.

When the leaf springs are secured, in accordance with the invention, sothat at least one of the leaf spring elements for one of the pressureplates is fastened at the housing, it is advisable, in accordance withthe invention, to fasten the bearing blocks mentioned and the leafsprings for at least one of the pressure plates, to the housing by meansof a common fastening element, such as a screw, for example.

With the aforementioned clutches, in accordance with another feature ofthe invention, the bearing of the two-arm levers of the otherdisengaging system, whereby these levers engage tension elements withtheir radially outer lever arm, is constructed in the form of a rockerbearing.

The rocker bearing support for the levers of this lever group isrealized in a particularly simple manner, according to the invention, byhaving these levers surround a pin disposed substantially parallel tothe axis, and received in the housing. It is particularly simple toprovide this pin, in accordance with the invention, with a knurl, and topress or drive it into a bore formed in the housing.

in such a case, the two-arm levers can also be in the form of profiledsheet metal parts.

In order to secure these levers in the radial direction against theeffect of centrifugal force, in accordance with an added feature of theinvention, the pin is received in a hole formed in the levers and thatis oval in radial direction. As viewed in direction of the periphery,the hole has a respective diameter matching the pin diameter, theradially inner region of the oval hole formed in the levers, providing acontact surface for the pins.

in accordance with yet another feature of the invention, these leversrest on a washer arrounding the pin or a plate or the like, in order toavoid direct contact with the casting. In this connection, it isparticularly appropriate if the plate, the washer or the like is formedof wear-resistant material, such as a case-hardened material.

In order to assure trouble-free rolling motion of the lever, inaccordance with the invention, the plate, the washer, or the like has aconvex surface. On the other hand, the lever can also be provided, inaccordance with the invention, at the surface of contact, with acambered or rounded convex surface or the like which faces the rollingor contact surface and with which the lever rests on a flat or alsocambered plate, a washer or the like.

In order to prevent the washer, plate or the like, from twistingrelative to the lever or the housing, respectively, it has been found tobe particularly advantageous, in accordance with the invention, toprovide means protecting against torsion between the lever and theplate. This protection device against torsion, which is of particularadvantage in the case of convex plates or washers, is formed, forexample, by providing the sheet metal lever with lateral walls that aredirected toward the housing for stiffening purposes and extend at leastpartially over the plate or disc.

The rocker bearing for the two-arm levers can, how ever, be formed, inaccordance with other features of the invention, also by a sphericalelement such as a ball, a roller, cylinder or the like, or can be amember having a surface formed in a similar manner, on which the leverrests with a correspondingly formed counterprofiled surface and canexecute the rolling motions.

A rocker bearing support can be formed also by providing at the lever,in accordance with the invention, an extension arm which extendssubstantially in direction of the axis of the clutch assembly and whichbears against the housing or engages in a recess formed in the housing,in which case it is advisable to provide in this recess a plate, awasher or the like of wear-resistant material with which thecorresponding extension arm is engageable. The extension arm is formed,for example, by a bracket consisting of the material of the lever, or byan angle fastened to the lever or the like, it being desirable that thecontact area be constructed as a knife edge and that the wear-resistantsupport such as, for example, the plate, washer or the like, can beformed at least in part with a V-shaped groove.

A knife-edge support for these two-arm levers is implemented also,according to the invention, by a bearing part which is fastened to thehousing and has a wall which projects substantially in axial directionof the clutch assembly, extends in peripheral direction and has at leastone profiled portion, against which the lever abuts with correspondinglycounter-profiled parts. Further in accordance with the invention, theprofiled parts are so formed that the lever is secured both inperipheral direction as well as in radial direction.

As mentioned hereinhefore, such a support of the levers is particularlyadvantageous because the levers can then be manufactured from relativelyinexpensive sheet metal profiled parts.

In accordance with additional features of the invention, the levers ofboth lever systems are provided with means for guiding the levers in thepivoting direction thereof and more specifically in the case of theone-arm levers, radially within the contact parts and, in the case ofthe two-arm levers, preferably within their bearing areas or rockerbearings, respectively.

Further in accordance with the invention, stops are provided in theradially inner lever region for limiting the tilting or pivoting motionof the levers in direction away from the housing. Additional features ofthe invention are to form the guide means and/or the stop means in theshape of a pin, the shaft of the pin serving as the guide means and thepin head as the stop means.

When the pin is used as the guide means, the stop for the lever can,however, also be formed, in accordance with the invention, by a snapring which is inserted into the shaft of the pin. The mounting andassembly of such a pin in the housing is particularly simple, when thepin is provided with a knurl, according to the invention, and the knurlportion is driven or pressed into a hole formed in the housing. Othertypes of press fits can, of course, also be effected, for example, bymeans of bushings, such as corrugated or slotted bushings, or the like.

A screw disposed in the housing can also be used as stop or guide means,respectively, in accordance with another feature of the invention.

In the friction clutches mentioned hereinhefore, it has already becomeknown to use spring clips for the tensioning of the levers, one arm ofthe spring clips bearing against the housing, and the other arm againstthe lever. A particularly advantageous construction is obtained,according to a further feature of the invention, when the arm of thespring clip bearing against the lever abuts a surface of the lever atsuch an inclination that a resultant is produced which causes theintermediate section between the two arms, such as the turn of thespring coil, to engage the housing in all operating positions of thelevers.

It is believed to be apparent that the invention can be implemented withthe manner of construction and operation of a dual clutch assemblydescribed hereinabove in an especially simple manner and that,furthermore, considerable simplifications and improvements as well aseconomical modes of manufacture thereof are provided as compared to theclutch assemblies of the same general type known herebefore. However, asnoted hereinhefore, the invention is not limited only to clutchassemblies according to the German Published Patent Application No.1,294,228, which has been referred to for the purpose of simplifying thedisclosure herein.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described therein as embodiedin friction clutch assembly, it is nevertheless not intended to belimited to the details shown, since various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.

The construction and method of operation of the iir vention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawing, in which:

FIG. 1 is a side view of an embodiment of the dual clutch of theinvention, partly broken away to show particular details thereof;

FIG. 2 is a cross-sectional view of FIG. 1 taken along a diametral planethereof represented by the line I] II, in the direction of the arrows;

FIG. 3 is a view similar to FIG. 1 of another embodiment of the dualclutch;

FIG. 4 is a view similar to FIG. 2 taken along the line IV IV in FIG. 3;

FIGS. 5 to 7 are, respectively, elevational, plan and sectional views ofa detail, namely the support member 17 of the embodiment of FIGS. 3 and4;

FIG. 8 is an enlarged plan view of another detail of FIGS. 3 and 4,namely the lever A; and

FIG. 9 is a cross-sectional view of FIG. 3 taken along the line IX IX inthe direction of the arrows.

The general construction of the clutches corresponding to that of theaforementioned German Published Patent Application are shown in thedrawings. Both embodiments of the clutches of FIGS. 1 and 3 aresubstantially of the same construction, but have differently disposedengagement devices for the shifting or disengaging means and torquetransmission means; these different constructions and arrangements willbe discussed hereinafter in greater detail.

Referring now to the drawings and more particularly to FIGS. 1 to 4thereof, there is shown two dual clutch assemblies, each having a clutchA for engaging and disengaging a gear-change transmission and a clutch Bfor engaging and disengaging a power take-off. Each of the clutches Aand B are provided with friction discs 1 and 2 and pressure plates 3 and4 which are equipped with friction surfaces. Between the two pressureplates 3 and 4, there is disposed a plate or disc spring 5 which bearsagainst dogs or bead-like projections 6 and 7, respectively, formed onthe two pressure plates 3 and 4, so that the friction discs I and 2 arepressed against friction countersurfaees, specifically against thefriction countersurface 8 provided at the housing 9 and against thefriction countcrsuface 10 of the flywheel 11. The housing 9 is fastenedto the flywheel 11 by screws (not shown), which pass through thefastening holes 12. To raise the pressure plates, two groups of levers Aand 8', each consisting of three levers, are distributed over thecircumference of the housing 9, and are pivotally mounted on the latter.

The levers A are one-armed and are disposed in such a way that if theyare turned in the direction of the arrow a they exert a pressure on thepressure plate 3 and raise the latter off the friction disc 1. Thelevers B are two-armed and are turned for the purpose of disengaging orreleasing the clutch, in the direction of the arrow b and accordinglyexert a pull through tension elements on the pressure plate 4, so thatthe latter is lifted off the disc 2 against the biasing force of theplate spring 5.

The levers A of FIGS. 1 and 2 form a knife-edge bearing, through theirradially outward extending lever arm A", with a support part 13. Aradially directed surface 15, which is provided at the wall 16, overlapsthe knife edge 14 of the levers A.

The levers A according to FIGS. 3 and 4 together with a support part 17,which is constructed as a bearing block, forms a knife-edge bearing.

With reference to FIGS. 5 to 7, this support part 17 is described ingreater detail, while the lever A is described in greater detail inreference to FIG. 8.

The support part or bearing block 17 has a wall 18 which projectssubstantially in the direction of the axis of the clutch assembly andextends in the peripheral or tengential direction. The bearing block isformed with profiled portions such as cutouts 19, at which the lever Aabuts with correspondingly shaped counterprofiled matching parts 20. Thelevers A are thereby secured at the bearing block 17 in peripheraldirection, axial direction and radial direction.

Radially within the bearing blocks 13 and 17 in FIGS. 1 to 4, the leversA have a contact element 21, in one instance a headless screw and in theother instance a regular screw that acts upon a pressure pin 22 whichfunctions as releasing or disengaging means for the levers of the onelever system A. The pin 22 is held in a guide 23 of the housing 9 with asliding fit. The end of the pin 22 facing away from the contact element21 is seated on the take-up means 24 (FIGS. 1 and 2) or 25 (FIGS. 3 and4), these take-up or engagement means 24, 25, respectively, beingprovided on dogs 26 (FIGS. 1 and 2) and 27 (FIGS. 3 and 4) formed on therespective pressure plates 3.

The contact elements 21 is adjustable in height by means of a threadedsleeve 28 formed with a flange 29, and a counternut 30. The lever A isclamped between the flange 29 and the counternut 30.

Each of the two-arm levers B engages, by its radially outer lever arm B,a pull member serving as a releasing means, namely, a bolt 31. Thesereleasing means 31 extend through a hole 32 formed in a dog 33 (FIGS. 1and 2) or a dog 34 (FIGS. 3 and 4) of the respective pressure plates 4.A nut 35 and a screw head 36, respectively, abut contact surfaces 37 and38, reseectively, of the dogs 33 and 34. The holes 32 and the contactsurfaces 37 and 38 function as the engagement take-up means,respectively, for the releasing or disengaging means 31 and 35', on theone hand, or 36, on the other hand.

The levers B are supported in the housing 9 by means of a rockerbearing. They are provided with a substantially spherical surface 39which engages a hardened washer 40, and are capable of swiveling on thiswasher. The levers B are respectively formed with an oval hole 42 which,in spherical direction, matches I the diameter of a pin 41 which isreceived therein, the radially inner region of this oval opening beingin abutting engagement with the pin 41 so that the lever B is therebysecured against the effect of the centrifugal force. The pins 41 areprovided with a knurled region 41a which is driven or pressed into abore 43 formed in the housing 9.

The levers A as well as the levers B are each formed with an opening 45,46 in their radially inner region through which respective pins 44extend. The pins 44 are formed with knurled portions 44, respectively,which are driven or pressed into bores 35 respectively formed in thehousing 9. The pins 44, in conjunction with the openings 45, 46 in thelevers A and B constitute a guide for the levers in the direction oftheir swinging or pivoting movement.

On the pins 44, snap rings 48 are provided which serve as stops forlimiting the swinging movement of the levers in direction facing awayfrom the housing 9.

The lever systems of both levers are tensioned or clamped by springclips 49. One of the force arms of the spring clip 49 is attached to thelevers, while the other force arm thereof is fixed to the housing 9. Theforce arm 50 bears against the contour surface 51 and 52, respectively,in FIGS. 1 and 2, and 53 and 54, respectively in FIGS. 3 and 4 of therespective levers A and B;, that is of such shape that a resultant isproduced which causes the center part of the spring clip 49, i.e., thehelical turns of each of the springs to abut against the housing 9 inall operating positions of the levers.

In dual clutches according to FIGS. 1 and 2, the press'ure plate 3 hasreceiving and engagement means 24 I for the releasing or disengagingmeans 22, the receiving and engagement means being provided on the dogs26 of the pressure plate 3. The pressure plate 3 has furthermore threereceiving means 55 in the form of dogs provided with holes for engagingand attaching, respectivley, the leaf springs 56. The leaf springs 56are secured at the housing, together with the leaf springs 57 for thepressure plate 4 and the bearing block 13, by

means of a screw or bolt 9a.

The leaf springs 57 are situated beneath and in registry with the leafsprings 56, and are each attached to dogs 58 which are disposed beneathand in registry with the dogs 55, and form with their holes thereceiving and engagement means, respectively, for the leaf springs Thepressure plate 3 has further additional receiving and engagement meansin the form of holes 59 and area portions 60 shown in dashed lines, oneach of the three dogs 26. The shifting or disengaging means 31 of theother shifting or engagement system, with which the levers B areassociated, can be engagedc at the receiving and engagement means 59 and60, respectively, if the pressure plate 3 is to be installed for theregular vehicle drive, i.e., for the transmission of'- the side of thepressure plate 4. I

The engagement means 60 are situated'on the same side of the pressureplate 3 as the engagement means 24, but they are offset with respect tothe engagement means 24 in radial and peripheral directions.

The pressure plate 4 has, as mentioned hereinbefore, engagement means 32and 37, which are provided at the dogs 33, for the releasing ordisengaging means 31 of the lever group B. In addition, this pressureplate 4 has also receiving or engagement means 61 for the releasing ordisengaging means of the lever group A, the pressure pins 22 beingengageable with the take-up or engagement means 61 if the pressure plate4 for the clutch B of the power take-off is to be installed on the 1side of the pressure plate 3. The engagement means 61 are offsetrelative to the engagement means32/37 in radial direction and arefurthermore mutually spaced from one another in peripheral direction,the spacing therebetwecn corresponding to the spacing which thereleasing or disengaging means of the individual releasing ordisengaging systems have from each other.

The engagement means 24 and 61 are disposed respectively on the samediameter, and so too are the engagement means 59, 60 and 32, 37.

The engagement means 55, 58 for the torque transmission means, or theircenters, respectively, which are simultaneously the centers of thefastening elements, i.e., the rivets 55' and 58, are disposed betweenthe adjacent releasing or disengaging means of the two shifting ordisengaging systems I and II, and specifically in the middle of theangular range between the take-up or engagement means disposed at bothpressure plates 3, 4 for the releasing or disengaging means ofrespectively one and the same shifting system l or II, i.e., between thetwo engagement means 24 and 61 and in the middle of the angular rangebetween the engagement means 60, 59 and 37, 32. In FIG. 1, the angle ashows that angle about which the engagement means 24 and 61 are spacedfrom each other, and the angle {3 shows that angle about which theengagement means or, the centers of the engagement means 59, 60 and 32,37 respectively, are spaced from each other. The line M shows the middleof the angular range in which the center of the engagement means 55, 58or the center of the rivets 55', 58' are situated. The engagement means24 and 59, 60, located on a common dog 26 of the pressure plate 3, ortheir centers, respectively, have a mutual angular spacing whichcorresponds to the difference of (1/2 and 8/2. The same also applies tothe engagement means located at the dog 33 of the pressure plate 4.

Both the engagement means 24 and 60 of the one pressure plate as well asthe engagement means 61 and 37 on the other pressure plate are locatedat the same height relative to the friction surfaces 3 and 4 of thepressure plates 3, 4. The two dimensions H, as shown in FIG. 2, aretherefore equal. Furthermore, the takeup means 55 and 58 for the torquetransmission means, i.e., the pads on which the leaf springs 56 and 57rest, are located practically at the same axial height relative to therespective friction surfaces 3 and 4'. The entire surface of the dogs26, 33 on which the take-up and engagement means 24, 60 and 61, 37 arelocated, are plane surfaces which can be produced, together with thesurfaces 55, 58 in one lathe operation.

It is apparent that the set of pressure plates 3, 4 can be arranged inreverse assembly position and that, using the same housings, the releaseor disengaging means as well as the torque transmission means and theengagement measn, respectively, and therefore suitable for this case ofreversed assembly installation.

In the case of dual clutches according to FIGS. 3 and 4, reversedassembly it also possible.

In this regard, middle engagement means at the pressure plate 3 serve inthe assembly position shown, as mentioned hereinbefore, for the supportand engagement of the pressure pins 22, while, for the tension element31, the hole 32 and the surface 34 serve as the engagement means at thepressure plate 4.

The pressure plate 3 is provided with three additional dogs 62, whichare each formed with a hole 63 as well as a surface 64, both of whichcorrespond to the .en-

gagement means 32 and 38 on the pressure plate 4. The Y dogs 62 as wellas the holes 63 are situated in registry with the dogs 34 and the holes32 of the pressure plate 4. The releasing or disengaging means 31 extendthrough the two holes 63 and 32 of the dogs 62 snd 34 and act only onthe pressure plate 4.

On each of the three dogs 65 of the pressure plate 4, which are situatedbeneat the three dogs 27 of the pressure plate 3, there is located anengagement means 66 corresponding to the engagement means 25, as amirror image with repsect to the line 67 and on the side of the dog 65facing the flywheel 11.

In the middle of the angular range between the centers of the engagementmeans 25 and 66, there are provided the centers of the engagement means,namely, of the holes 68 and 69 and the support surfaces 70 and 71 forthe leaf springs 72 and 73. The angular spacing is indicated at a, whilethe bisector 67 represents the line on which the leaf springs arefastened on the pressure plates 3 and 4. The leaf springs are screwed tothe housing 9 by means of screws 76, as is shown more clearly in thecross-sectional view of FIG. 9 which is taken along the line IX IX inFIG. 3.

The centers of the fastening elements for the leaf springs are alsosituated in the middle of the angular range between the centers of theother releasing or disengaging means 31 as is shown by the lines 76, 77and 78. It, is apparent that the angle B corresponds to twice the angleB'IZ and that the center of the fastening means for the leaf springs 74and 75 is situated on the bisector 77.

If the pressure plates are reversed, for example, about the axis 67, thepressure pins 22 now come into engagement at the engagement means 66 ofthe pressure plate 4, while the releasing or disengaging means 31 of thelever system B engage with the take-up and engagement means 63 and 64,respectively, of the pressure plate 4.

The engagement means 25, 66, 38, 64 as well as 70, 71 are in each caselocated at the same height relative to the friction surfaces 3 and 4.The dimensions H are equal, and so are the dimensions H It is apparentthat if the pressure plates are reversed, all of the individual parts orcomponents can be used in the same manner as in the assembly positionshown in FIGS. 3 and 4.

I claim:

1. Friction clutch assembly for motor vehicles, tractors, equipmentcarriers and similar vehicles having a first friction clutch forengaging and disengaging a gear-change transmission, a second clutch foran additional drive, each of the clutches including a friction disc, aspring-loaded pressure plate having a friction surface and beingcoordinated with each of said friction discsfr esp'ectively, an axiallyfixed structural unit for connecting one of said clutches to afly-wheel, torque transmitting means located in a power transmissionpath between the flywheel or the axially fixed structural unit, on theone hand, and said spring-loaded pressure plates, on the other hand, anda disengaging lever system for each of the clutches, the disengaginglever systems having a respective disengaging means, the improvementwherein said pressure plates respectively are provided with receivingand engagement means for receiving the disengaging means of either ofthe clutches in which the respective pressure plates are then assembled,and engageable by the torque transmitting means in whichever clutch thepressure plates are assembled, whereby the pressure plate of the firstfriction clutch and the pressure plate of the second friction clutch aremutually exchangeable in another assembled condition of the frictionclutch assembly.

2. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch are spaced respectively an equalangular distance apart on both of the pressure plates.

3. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch are disposed on both pressureplates on the same diameter, respectively, thereof.

4. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch as well as the torque transmittingmeans are spaced respectively an equal angular distance apart on both ofthe pressure plates.

5. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch as well as the receiving means forthe torque transmitting means are spaced respectively an equal angulardistance apart on both of the pressure plates.

6. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch as well as the torque transmittingmeans are disposed on the same diameter respectively, on both pressureplates.-

7. Friction clutch assembly according to claim 1 wherein the receivingmeans for the disengaging means of the one clutch and for thedisengaging means of the other clutch as well as the receiving means forthe torque transmitting means are disposed on the diameter,respectively, on both pressure plates.

8. Friction clutch assembly according to claim 1 wherein the receivingmeans at both of the pressure plates are located at the same height withrespect to the friction surfaces of the respective pressure plates.

9. Friction clutch assembly according to claim 1 including leaf springmeans disposed in the power transmission path, and receiving andengagement means located on said pressure plates for receiving said leafspring means in the middle of the angular region located between twoadjacent disengaging means.

10. Friction clutch assembly according to claim 1 wherein at eachindividual pressure plate, the receiving and engagement means,respectively, provided for the disengaging means of the one disengagingsystem spaced angularly from the receiving and engagement means,respectively, provided for the disengaging means of the otherdisengaging system.

11. Friction clutch assembly according to claim 1 wherein at eachindividual pressure plate, the receiving and engagement means,respectively, provided for the disengaging means of the one disengagingsystem are radially spaced from the receiving and engagment means,respectively, provided for the disengaging means of the otherdisengaging system.

12. Friction clutch according to claim 1 wherein, at both pressureplates, the receiving and engagement means for the disengaging means ofthe same disengaging system are located at the same radial level.

13. Friction clutch according to claim 12 wherein engagement means fortorque transmission are located between adjacent disengaging means ofboth disengaging systems at each of the pressure plates, in the middleof the angular range between the receiving and engagement means,respectively, provided at both pressure plates, for one of thedisengaging systems, respectively.

14. Friction clutch according to claim 1 wherein the engagement meansfor said torque transmission means is located in registry with andsuperimposed on one another at both pressure plates.

15. Friction clutch assembly according to claim l4 including additionalengagement means for the disengaging means of the other disengagingsystem, said torque transmission means comprising leaf springs, andfastening elements for said leaf springs to said pressure plates, thecenter of said fastening elements being in the middle of the angularrange between the centers of the adjacent disengaging means of one ofsaid disengaging systems.

16. Friction clutch assembly according to claim 15 wherein theengagement means of one of said disengaging systems, in said otherassembly condition of the friction clutch assembly, serves as engagementmeans for said leaf spring elements and vice versa.

17. Friction assembly according to claim 16 wherein the engagement meansfor the disengaging means of one of said disengaging systems, and theengagement means for said leaf springs are located on a common radiallyprojecting element of said pressure plates.

18. Friction clutch assembly according to claim 16 wherein saidengagement means for said leaf springs are located in the middle of theangular range between the engagement means for the disengaging means ofone of said disengaging systems.

19. In a friction clutch assembly according to claim 1 wherein a platespring is provided between said two pressure plates in bearingengagement with bead-like projections formed on said pressure plates,the flywheel serving as friction counter-surface member for one of saidfriction discs, and the counter-surface of said other friction disc islocated in said housing, which at least partly encloses the clutches,the disengaging system for each of the clutches including a one and atwo-arm levcr, said levers being pivoted in said housing, said onearmlevers exerting pressure on one of said pressure plates, and saidtwo-arm levers exerting a pull on the other pressure plate, said one-armlevers forming a knife-edge bearing with a respective bearing elementlocated at said housing.

20. Friction clutch assembly according to claim 19 wherein said bearingelements are in the form of bearing blocks having a respective wallprojecting substantially in direction of the axis of the clutch assemblyand extending in tangential direction thereto, said bearing elementshaving at least one profiled portion, respectively, engageable by acorresponding counter-profiled portion of said levers.

21. Friction clutch assembly according to claim 20 wherein said leversare formed of sheet metal profiled members.

22. Friction clutch assembly according to claim 20 wherein said bearingblocks are formed of sheet metal profiled members.

23. Friction clutch assembly according to claim 20 wherein said levershave a contact part extending radially into said bearing blocks, apressure pin slidingly held in a guide of said housing and engageable atone end by said contact part, said pressure pin having an end facingaway from said contact part and abutting the receiving and engagementmeans of the one pressure plate.

24. Friction clutch assembly according to claim 23 wherein said contactpart is adjustable in height.

25. Friction clutch assembly according to claim 23 wherein said contactpart is located in a threaded bushing provided at said lever.

26. Friction assembly according to claim 25 wherein said threadedbushing has a flange which abuts against a side of said lever facingtoward said housing, and is provided with a counternut on the other sideof said lever.

27. Friction clutch assembly according to claim 26 including a commonfastening element fastening said bearing blocks and the leaf springs forat least one of the pressure plates to said housing.

28. Friction clutch assembly according to claim 19 including bearingsfor said two-arm levers, said bearings being in the form of rockerbearings.

29. Friction clutch assembly according to claim 28 wherein said leverssurround a pin extending substantially parallel to the axis of thefriction clutch assembly and received in said housing.

30. Friction clutch assembly according to claim 29 whereinr said pin isformed with a knurled portion press-fitted into a bore formed in saidhousing.

31. Friction clutch assembly according to claim 30 wherein said pin isreceived in a hole formed in said levers, said hole being oval andhaving its longer axis extending in radial direction of the frictionclutch assembly, said hole, as viewed in peripheral direction having adiameter matching the diameter of said pin, said oval hole having aradially inner edge formed in said levers and providing a contactsurface for said pins.

32. Friction clutch assembly according to claim 31 including a platelikemember surrounding said pin and engaged by said lever.

33. Friction clutch assembly according to claim 32 wherein saidplatelike member has a substantially convex surface.

34. Firction clutch assembly according to claim 33 wherein said leverhas a flat surface with respect to said platelike member.

35. Friction clutch assembly according to claim 32 wherein saidplatelike member is formed of wearresistant material.

36. Friction clutch assembly according to claim 19, including meansprotecting against torsion between said lever and said platelike member.

37. Friction clutch assembly according to claim 28 wherein said rockerbearing is formed by a spherical element, said lever having acorresponding counterprofiled surface in engagement therewith.

38. Friction clutch assembly according to claim 28 including anextension arm at said lever, extending substantially in direction of theaxis of the clutch assembly and bearing against said housing.

39. Friction clutch assembly according to claim 38 including a platelikemember of wear-resistant material located at said housing, saidextension arm being engageable with said platelike member.

40. Friction clutch assembly according to claim 28, including a bearingpart fastened to said housing and forming with said lever a knife-edgebearing, said bearing part having a wall extending substantially inperipheral direction and having at least one profiled portion abuttableby correspondingly profiled parts formed on said lever.

41. Friction clutch assembly accordingto claim 40 wherein said leversare formed of sheet metal profiled members.

42. Friction clutch assembly according to claim 23 including means forguiding said levers in pivoting direction thereof located radial withinsaid contact parts and bearing areas.

43. Friction clutch assembly according to claim 42 including stop meanslocated in the radially inner region of said levers for limitingpivoting movement of said levers in direction away from said housing.

44. Friction clutch assembly according to claim 43 wherein said guidemeans is formed by a pin.

45. Friction clutch assembly according to claim 44 wherein said stopmeans comprises a head formed on said pin.

46. Friction clutch assembly according to claim 45 wherein said stopmeans comprises a snap ring secured to said pin.

Jamaica clutch assembly according to claim 46 wherein said pin issecured by a press fit in a bore formed in said housing.

48. Friction clutch assembly according to claim 47 wherein said pin isformed with a knurled portion with which it is press-fitted into saidbore formed in said housing.

49. Friction clutch assembly according to claim 42 wherein said guidemeans is formed by a screw located in said housing.

50. Friction clutch assembly according to claim 19 including springclips for tensioning said levers, and spring clips, respectively, havingan arm bearing against said housing, and another arm bearing againstsaid levers, said arm bearing against said levers being in abuttingengagement with a surface of said leversat such an inclination that aresultant force is produced causing a section of said spring clipslocated between said two arms thereof to abut said housing in alloperating positions of said levers.

1. Friction clutch assembly for motor vehilces, tractors, equipmentcarriers and similar vehicles having a first friction clutch forengaging and disengaging a gear-change transmission, a second clutch foran additional drive, each of the clutches including a friction disc, aspring-loaded pressure plate having a friction surface and beingcoordinated with each of said friction discs, respectively, and axiallyfixed structural unit for connecting the second clutch to a fly-wheel,torque or transmitting means located in a power transmission pathbetween the flywheel or the axially fixed structural unit, on the onehand, and said spring-loaded pressure plates, on the other hand, and adisengaging lever system for each of the clutches, the disengaging leversystems having a respective disengaging means, the improvement whereinsaid pressure plates respectively are provided with receiving andengagement means for receiving the disengaging means of either of theclutches in which the respective pressure plates are then assembled, andengageable by the torque transmitting means in whichever clutch thepressure plates are assembled, whereby the pressure plate of the firstfriction clutch and the pressure plate of the second friction clutch aremutually exchangeable in another assembled condition of the frictionclutch assembly.
 2. Friction clutch assembly according to claim 1wherein the receiving means for the disengaging means of the one clutchand for the disengaging means of the other clutch are spacedrespectively an equal angular distance apart on both of the pressureplates.
 3. Friction clutch assembly according to claim 1 wherein thereceiving means for the disengaging means of the one clutch and foR thedisengaging means of the other clutch are disposed on both pressureplates on the same diameter, respectively, thereof.
 4. Friction clutchassembly according to claim 1 wherein the receiving means for thedisengaging means of the one clutch and for the disengaging means of theother clutch as well as the torque transmitting means are spacedrespectively an equal angular distance apart on both of the pressureplates.
 5. Friction clutch assembly according to claim 1 wherein thereceiving means for the disengaging means of the one clutch and for thedisengaging means of the other clutch as well as the receiving means forthe torque transmitting means are spaced respectively an equal angulardistance apart on both of the pressure plates.
 6. Friction clutchassembly according to claim 1 wherein the receiving means for thedisengaging means of the one clutch and for the disengaging means of theother clutch as well as the torque transmitting means are disposed onthe same diameter respectively, on both pressure plates.
 7. Frictionclutch assembly according to claim 1 wherein the receiving means for thedisengaging means of the one clutch and for the disengaging means of theother clutch as well as the receiving means for the torque transmittingmeans are disposed on the diameter, respectively, on both pressureplates.
 8. Friction clutch assembly according to claim 1 wherein thereceiving means at both of the pressure plates are located at the sameheight with respect to the friction surfaces of the respective pressureplates.
 9. Friction clutch assembly according to claim 42 wherein saidguide means is formed by a screw located in said housing.
 9. Frictionclutch assembly according to claim 1 including leaf spring meansdisposed in the power transmission path, and receiving and engagementmeans located on said pressure plates for receiving said leaf springmeans in the middle of the angular region located between two adjacentdisengaging means.
 10. Friction clutch assembly according to claim 1wherein at each individual pressure plate, the receiving and engagementmeans, respectively, provided for the disengaging means of the onedisengaging system spaced angularly from the receiving and engagementmeans, respectively, provided for the disengaging means of the otherdisengaging system.
 11. Friction clutch assembly according to claim 1wherein at each individual pressure plate, the receiving and engagementmeans, respectively, provided for the disengaging means of the onedisengaging system are radially spaced from the receiving and engagmentmeans, respectively, provided for the disengaging means of the otherdisengaging system.
 12. Friction clutch according to claim 1 wherein, atboth pressure plates, the receiving and engagement means for thedisengaging means of the same disengaging system are located at the sameradial level.
 13. Friction clutch according to claim 12 whereinengagement means for torque transmission are located between adjacentdisengaging means of both disengaging systems at each of the pressureplates, in the middle of the angular range between the receiving andengagement means, respectively, provided at both pressure plates, forone of the disengaging systems, respectively.
 14. Friction clutchaccording to claim 1 wherein the engagement means for said torquetransmission means is located in registry with and superimposed on oneanother at both pressure plates.
 15. Friction clutch assembly accordingto claim 14 including additional engagement means for the disengagingmeans of the other disengaging system, said torque transmission meanscomprising leaf springs, and fastening elements for said leaf springs tosaid pressure plates, the center of said fastening elements being in themiddle of the angular range between the centers of the adjacentdisengaging means of one of said disengaging systems.
 16. Frictionclutch assembly according to claim 15 wherein the engagement means ofone of said disengaging systems, in said other assembly condition of thefriction clutch assembly, serves as engagement means for said leafspring elements and vice Versa.
 17. Friction assembly according to claim16 wherein the engagement means for the disengaging means of one of saiddisengaging systems, and the engagement means for said leaf springs arelocated on a common radially projecting element of said pressure plates.18. Friction clutch assembly according to claim 16 wherein saidengagement means for said leaf springs are located in the middle of theangular range between the engagement means for the disengaging means ofone of said disengaging systems.
 19. In a friction clutch assemblyaccording to claim 1 wherein a plate spring is provided between said twopressure plates in bearing engagement with bead-like projections formedon said pressure plates, the flywheel serving as frictioncounter-surface member for one of said friction discs, and thecounter-surface of said other friction disc is located in said housing,which at least partly encloses the clutches, the disengaging system foreach of the clutches including a one and a two-arm lever, said leversbeing pivoted in said housing, said one-arm levers exerting pressure onone of said pressure plates, and said two-arm levers exerting a pull onthe other pressure plate, said one-arm levers forming a knife-edgebearing with a respective bearing element located at said housing. 20.Friction clutch assembly according to claim 19 wherein said bearingelements are in the form of bearing blocks having a respective wallprojecting substantially in direction of the axis of the clutch assemblyand extending in tangential direction thereto, said bearing elementshaving at least one profiled portion, respectively, engageable by acorresponding counter-profiled portion of said levers.
 21. Frictionclutch assembly according to claim 20 wherein said levers are formed ofsheet metal profiled members.
 22. Friction clutch assembly according toclaim 20 wherein said bearing blocks are formed of sheet metal profiledmembers.
 23. Friction clutch assembly according to claim 20 wherein saidlevers have a contact part extending radially into said bearing blocks,a pressure pin slidingly held in a guide of said housing and engageableat one end by said contact part, said pressure pin having an end facingaway from said contact part and abutting the receiving and engagementmeans of the one pressure plate.
 24. Friction clutch assembly accordingto claim 23 wherein said contact part is adjustable in height. 25.Friction clutch assembly according to claim 23 wherein said contact partis located in a threaded bushing provided at said lever.
 26. Frictionassembly according to claim 25 wherein said threaded bushing has aflange which abuts against a side of said lever facing toward saidhousing, and is provided with a counternut on the other side of saidlever.
 27. Friction clutch assembly according to claim 26 including acommon fastening element fastening said bearing blocks and the leafsprings for at least one of the pressure plates to said housing. 28.Friction clutch assembly according to claim 19 including bearings forsaid two-arm levers, said bearings being in the form of rocker bearings.29. Friction clutch assembly according to claim 28 wherein said leverssurround a pin extending substantially parallel to the axis of thefriction clutch assembly and received in said housing.
 30. Frictionclutch assembly according to claim 29 whereinr said pin is formed with aknurled portion press-fitted into a bore formed in said housing. 31.Friction clutch assembly according to claim 30 wherein said pin isreceived in a hole formed in said levers, said hole being oval andhaving its longer axis extending in radial direction of the frictionclutch assembly, said hole, as viewed in peripheral direction having adiameter matching the diameter of said pin, said oval hole having aradially inner edge formed in said levers and providing a contactsurface for said pins.
 32. Friction clutch assembly according to claim31 including a platelike member surrounding saiD pin and engaged by saidlever.
 33. Friction clutch assembly according to claim 32 wherein saidplatelike member has a substantially convex surface.
 34. Firction clutchassembly according to claim 33 wherein said lever has a flat surfacewith respect to said platelike member.
 35. Friction clutch assemblyaccording to claim 32 wherein said platelike member is formed ofwear-resistant material.
 36. Friction clutch assembly according to claim19, including means protecting against torsion between said lever andsaid platelike member.
 37. Friction clutch assembly according to claim28 wherein said rocker bearing is formed by a spherical element, saidlever having a corresponding counter-profiled surface in engagementtherewith.
 38. Friction clutch assembly according to claim 28 includingan extension arm at said lever, extending substantially in direction ofthe axis of the clutch assembly and bearing against said housing. 39.Friction clutch assembly according to claim 38 including a platelikemember of wear-resistant material located at said housing, saidextension arm being engageable with said platelike member.
 40. Frictionclutch assembly according to claim 28, including a bearing part fastenedto said housing and forming with said lever a knife-edge bearing, saidbearing part having a wall extending substantially in peripheraldirection and having at least one profiled portion abuttable bycorrespondingly profiled parts formed on said lever.
 41. Friction clutchassembly accordingto claim 40 wherein said levers are formed of sheetmetal profiled members.
 42. Friction clutch assembly according to claim23 including means for guiding said levers in pivoting direction thereoflocated radial within said contact parts and bearing areas.
 43. Frictionclutch assembly according to claim 42 including stop means located inthe radially inner region of said levers for limiting pivoting movementof said levers in direction away from said housing.
 44. Friction clutchassembly according to claim 43 wherein said guide means is formed by apin.
 45. Friction clutch assembly according to claim 44 wherein saidstop means comprises a head formed on said pin.
 46. Friction clutchassembly according to claim 45 wherein said stop means comprises a snapring secured to said pin.
 46. Friction clutch assembly according toclaim 46 wherein said pin is secured by a press fit in a bore formed insaid housing.
 48. Friction clutch assembly according to claim 47 whereinsaid pin is formed with a knurled portion with which it is press-fittedinto said bore formed in said housing.
 50. Friction clutch assemblyaccording to claim 19 including spring clips for tensioning said levers,and spring clips, respectively, having an arm bearing against saidhousing, and another arm bearing against said levers, said arm bearingagainst said levers being in abutting engagement with a surface of saidlevers at such an inclination that a resultant force is produced causinga section of said spring clips located between said two arms thereof toabut said housing in all operating positions of said levers.